You remind me of Ricky Gervais in Extras.
I do really dislike that bloke.
That isn't commonly done here.
Criminy, you have expensive dreams.
I think there's an approach which is both better & cheaper.
OMG..... see why you lot are where you're at?
You want to spend tuppence, and then it costs you masses, in lives, responses, investigations, reparations and damages.
Military types (in my hiring experience) aren't all that capable.
So because you hired some military types for property-services work or whatever, you now think they won't be suitable for guarding duties?
And their training is inappropriate.
Their training is clearly beyond your recognition of what suitable training is. They've mostly been trained to do what they've been told to do, when they need to do it, how they're supposed to do it.
If you had been, say, a rifleman, who when under fire has first to communicate to a commanding officer and then wait for confirmation that return fire is supportable by top brass (oh yes, our guys n girls in Northern Ireland often experienced that kind of situation, as well as yours in the Gulf), then you're getting an operative who will probably be many times more cool than a history master.
Private security types are typically the dregs of society.
You're not hiring security officers for their position in society, you would be hiring them, inducting them, training them, selecting them and supporting them to do a very seriously important job.
You only get cr-p guards when you give them cr-p training and crap working conditions.
If you think guards are cr-p then you don't deserve better.
Police are expensive to have on site all the time.
The tight-wad approach has costed 50 school shootings in a year. Pay up for the lives of kids, and get a common-sense bunch of gun controls sorted.
Vetted & trained schools staff look to be the best solution because of cost & function.
Of course some large inner city schools could take the spendier approach.
Vetted and trained security staff can give their total attention to the objectives of access-control, conflict reduction and health-safety in the workplace.
It's time to show that you really care about your kids, before your gun-freedoms, maybe?